CN110661610B - Input acquisition method and device of secure multi-party computing protocol - Google Patents

Abstract

The embodiments of this specification provide a method and device for obtaining the input of a secure multi-party computation protocol. The participants of the secure multi-party computation protocol include a first server, and the first server is the server of the first object. The secure multi-party computation protocol is based on The first data of the first object is calculated, wherein the first data is stored in the second server side, the second server side is the server side of the authoritative organization, and the method is executed on the second server side, including: from the first The server receives a data request for the first data; based on the data request, homomorphically encrypts the first data by using the public key received from the first server in advance to generate a first ciphertext, wherein the public key is the first ciphertext. A homomorphic encryption public key of an object; obtaining verification data based on the first ciphertext, and the verification data is used to verify whether the ciphertext to be verified corresponds to the first data; and sending the verification data to the first server.

Description

Input acquisition method and device for secure multi-party computation protocol

technical field

The embodiments of the present specification relate to the technical field of cryptography, and more particularly, to a method and apparatus for obtaining the input of a secure multi-party computation protocol.

Background technique

An entity (individual or enterprise, organization) usually needs to provide its own private data (age, deposit, gender, income) to another entity (or multiple entities or even the public) when applying for loans, applying for visas, filing taxes, etc. , for calculation/evaluation by another entity (or entities or even the public). The former entity may be referred to as the prover, and the latter entity may be referred to as the verifier. The proving party may lie when providing data, so one or more entities (endorsing parties) are required to provide proof, such as deposit certificates provided by bank endorsers, ID cards/business licenses provided by government endorsers, etc.

When the prover submits its private data to the verifier for calculation/evaluation, the prover will worry about privacy leakage. If another method is adopted, the calculation/evaluation method is handed over to the prover, and the prover only provides the calculation result to the verifier, then there is the possibility of the prover falsifying, and the prover may use false data for calculation, which may not be faithful Calculate according to the calculation method provided.

In order to solve the above-mentioned contradiction between data privacy and data credibility, the existing technology uses a combination of zero-knowledge proof, hash, digital signature and blockchain technology. When the endorser stores the data of the prover, it records the hash value of the data and its digital signature for the hash value in the blockchain ledger. In order to prevent exhaustive attacks caused by too small data value space, random numbers are used in hashing. The certificate of deposit sent by the endorser to the prover includes the hash value, the random number used for hashing, the location recorded in the blockchain ledger, and optionally the digital signature of the hash value. The certificate of deposit sent by the prover to the verifier contains the hash value, the location recorded in the blockchain ledger, and optionally the digital signature of the hash value. Then, through the zero-knowledge proof technology, the verifier can verify that the data used by the prover in the process of calculating the function f matches the hash value in the certificate of deposit, and the prover does not use other functions to replace f in the calculation, The f function is faithfully executed. Therefore, the verifier finally obtains a credible calculation result. This process requires powerful zero-knowledge proof technology, which requires more computing and storage resources.

Therefore, there is a need for a more efficient scheme for obtaining the input of a secure multi-party computation protocol.

SUMMARY OF THE INVENTION

The embodiments of the present specification aim to provide a more effective method and apparatus for obtaining the input of a secure multi-party computation protocol, so as to solve the deficiencies in the prior art.

In order to achieve the above object, one aspect of this specification provides a method for obtaining the input of a secure multi-party computation protocol, wherein the participants of the secure multi-party computation protocol include a first server, and the first server is the server of the first object. , the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the second server side, the second server side is the server side of the authoritative organization, so The method is executed on the second server, including:

receiving a data request for the first data from the first server;

Based on the data request, perform homomorphic encryption on the first data by using the public key previously received from the first server to generate a first ciphertext, where the public key is the first object's Homomorphic encryption public key;

Obtain verification data based on the first ciphertext, where the verification data is used to verify whether the ciphertext to be verified corresponds to the first data; and

Send the verification data to the first server.

Another aspect of this specification provides a method for obtaining input of a secure multi-party computation protocol, wherein the participants of the secure multi-party computation protocol include a first server end and a third server end, and the first server end is a server of a first object end, the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in a second server end, and the second server end is the server end of an authoritative organization, The method is executed on the first server, including:

sending a data request for the first data to the second server;

obtaining a second ciphertext corresponding to the first data, wherein the second ciphertext is a homomorphically encrypted ciphertext obtained by using the pre-generated public key of the first object;

receiving from the second server authentication data obtained according to the method of obtaining the input of the secure multi-party computation protocol according to any of the above; and

Send the second ciphertext and the verification data to the third server.

Another aspect of this specification provides a method for obtaining input of a secure multi-party computation protocol, wherein the participants of the secure multi-party computation protocol include a first server end and a third server end, and the first server end is a server of a first object end, the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in a second server end, and the second server end is the server end of an authoritative organization, The method is executed on the first server, including:

sending a data request for the first data to the second server;

receiving, from the second server, the ledger location storing the first ciphertext and the authority's digital signature on the first ciphertext; and

Sending the ledger location to the third server.

Another aspect of this specification provides a method for obtaining input of a secure multi-party computation protocol, wherein the participants of the secure multi-party computation protocol include a first server end and a third server end, and the first server end is a server of a first object end, the secure multi-party computation protocol performs computation based on first data of the first object, wherein the first data is stored in the first server end, and the method is executed at the first server end ,include:

Obtain the ciphertext corresponding to the first data by performing homomorphic encryption on the first data by using the pre-generated public key of the first object;

By depositing the ciphertext in the blockchain, obtaining the location of the ledger where the ciphertext is stored in the blockchain; and

Send the ciphertext and the location of the ledger to the third server.

Another aspect of this specification provides a method for obtaining input of a secure multi-party computation protocol, wherein the participants of the secure multi-party computation protocol include a first server end and a third server end, and the first server end is a server of a first object end, the secure multi-party computation protocol performs computation based on first data of the first object, wherein the first data is stored in the first server end, and the method is executed at the first server end ,include:

Obtain the ciphertext corresponding to the first data by performing homomorphic encryption on the first data by using the pre-generated public key of the first object;

By storing the ciphertext and the digital signature of the first object on the ciphertext in the blockchain, the location of the ledger where the ciphertext and the digital signature are stored in the blockchain is obtained, wherein the a digital signature is generated by the first server; and

Sending the ledger location to the third server.

Another aspect of this specification provides a method for obtaining input of a secure multi-party computation protocol, wherein the participants of the secure multi-party computation protocol include a first server end and a third server end, and the first server end is a server of a first object end, the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in a second server end, and the second server end is the server end of an authoritative organization, The method is executed on the third server, including:

Receive from the first server the second ciphertext and the verification data obtained by the method performed on the first server as described above;

verifying the second ciphertext using the verification data to determine whether the second ciphertext corresponds to the first data; and

In the case where it is determined that the second ciphertext corresponds to the first data, it is determined that the second ciphertext is used as the input of the secure multi-party computation protocol.

Another aspect of this specification provides a method for obtaining input of a secure multi-party computation protocol, wherein the participants of the secure multi-party computation protocol include a first server end and a third server end, and the first server end is a server of a first object end, the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in a second server end, and the second server end is the server end of an authoritative organization, The method is executed on the third server, including:

receiving, from the first server, the ledger location storing the first ciphertext and the authoritative authority's digital signature on the first ciphertext; and

The first ciphertext is obtained from the ledger location as an input to the secure multi-party computation protocol.

Another aspect of this specification provides a method for obtaining input of a secure multi-party computation protocol, wherein the participants of the secure multi-party computation protocol include a first server end and a third server end, and the first server end is a server of a first object end, the secure multi-party computation protocol performs computation based on first data of the first object, wherein the first data is stored in the first server end, and the method is executed at the third server end ,include:

Receive, from the first server, the ciphertext and the ledger location obtained by the method performed on the first server as described above;

verifying the ciphertext using the ledger location to determine whether the ciphertext corresponds to the first data; and

In the case where it is determined that the ciphertext corresponds to the first data, it is determined that the ciphertext is used as the input of the secure multi-party computation protocol.

Another aspect of this specification provides a method for obtaining input of a secure multi-party computation protocol, wherein the participants of the secure multi-party computation protocol include a first server end and a third server end, and the first server end is a server of a first object end, the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the first server end, and the method is executed at the third server end, including :

receiving from the first server the location of the ledger obtained by the method performed on the first server; and

The ciphertext is obtained from the ledger location as an input to the secure multi-party computation protocol.

Another aspect of the present specification provides a device for obtaining input of a secure multi-party computation protocol, wherein a participant of the secure multi-party computation protocol includes a first server, the first server is a server of a first object, and the secure The multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the second server side, the second server side is the server side of the authoritative organization, and the device is located in the The second server-side implementation described above includes:

a receiving unit, configured to receive a data request for the first data from the first server;

A generating unit, configured to, based on the data request, perform homomorphic encryption on the first data by using a public key previously received from the first server to generate a first ciphertext, wherein the public key is the homomorphic encryption public key of the first object;

an obtaining unit configured to obtain verification data based on the first ciphertext, where the verification data is used to verify whether the ciphertext to be verified corresponds to the first data; and

A sending unit, configured to send the verification data to the first server.

In one embodiment, in the apparatus for obtaining the input of the secure multi-party computation protocol, the data request includes a random number for performing homomorphic encryption on the first data, and the generating unit is further configured to , performing homomorphic encryption on the first data by using the public key and the random number received from the first server in advance to generate a first ciphertext.

In one embodiment, in the apparatus for obtaining the input of the secure multi-party computation protocol, the sending unit is further configured to send the verification data and the first ciphertext to the first server.

In one embodiment, in the device for obtaining the input of the secure multi-party computation protocol, the obtaining unit is further configured to obtain the first ciphertext in the blockchain by storing the certificate in the blockchain. The location of the ledger where the first ciphertext is stored is used as the verification data.

Another aspect of the present specification provides a device for obtaining input of a secure multi-party computation protocol, where participants of the secure multi-party computation protocol include a first server and a third server, and the first server is a server of a first object end, the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in a second server end, and the second server end is the server end of an authoritative organization, The apparatus is implemented on the first server side, including:

a first sending unit, configured to send a data request for the first data to the second server;

an obtaining unit, configured to obtain a second ciphertext corresponding to the first data, wherein the second ciphertext is a homomorphically encrypted ciphertext obtained by using a pre-generated public key of the first object;

a receiving unit configured to receive, from the second server side, the verification data obtained according to any one of the methods performed on the second server side according to the above; and

The second sending unit is configured to send the second ciphertext and the verification data to the third server.

In one embodiment, in the apparatus for acquiring the input of the secure multi-party computation protocol, the acquiring unit is further configured to receive, from the second server side, the said The first ciphertext is used as the second ciphertext.

In one embodiment, in the device for obtaining the input of the secure multi-party computation protocol, the first server stores the first data, and wherein the obtaining unit is further configured to locally pass the Homomorphically encrypt the first data with the public key and a locally generated random number to obtain the second ciphertext, wherein the random number is included in the data request for the first data.

Another aspect of the present specification provides a device for obtaining input of a secure multi-party computation protocol, where participants of the secure multi-party computation protocol include a first server and a third server, and the first server is a server of a first object end, the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in a second server end, and the second server end is the server end of an authoritative organization, The apparatus is executed on the first server side, including:

a first sending unit, configured to send a data request for the first data to the second server;

a receiving unit configured to receive, from the second server, the location of the ledger by storing the first ciphertext and the digital signature of the authoritative authority on the first ciphertext; and

The second sending unit is configured to send the account book location to the third server.

Another aspect of the present specification provides a device for obtaining input of a secure multi-party computation protocol, where participants of the secure multi-party computation protocol include a first server and a third server, and the first server is a server of a first object end, the secure multi-party computation protocol performs computation based on first data of the first object, wherein the first data is stored in the first server end, and the apparatus executes the first server end ,include:

an encryption unit, configured to perform homomorphic encryption on the first data by using the pre-generated public key of the first object to obtain a ciphertext corresponding to the first data;

a certificate depositing unit, configured to obtain the location of the ledger where the ciphertext is stored in the blockchain by depositing the ciphertext in the blockchain; and

A sending unit, configured to send the ciphertext and the location of the ledger to the third server.

Another aspect of the present specification provides a device for obtaining input of a secure multi-party computation protocol, where participants of the secure multi-party computation protocol include a first server and a third server, and the first server is a server of a first object end, the secure multi-party computation protocol performs computation based on first data of the first object, wherein the first data is stored in the first server end, and the apparatus implements the first server end ,include:

an encryption unit, configured to perform homomorphic encryption on the first data by using the pre-generated public key of the first object to obtain a ciphertext corresponding to the first data;

a depositing unit, configured to obtain the ciphertext and the digital signature stored in the blockchain by depositing the ciphertext and the digital signature of the first object on the ciphertext in the blockchain , where the digital signature is generated by the first server side; and

A sending unit, configured to send the account book location to the third server.

Another aspect of the present specification provides a device for obtaining input of a secure multi-party computation protocol, where participants of the secure multi-party computation protocol include a first server and a third server, and the first server is a server of a first object end, the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in a second server end, and the second server end is the server end of an authoritative organization, The apparatus is implemented on the third server, including:

a receiving unit, configured to receive, from the first server, the second ciphertext and the verification data obtained by the method performed on the first server;

a verification unit configured to verify the second ciphertext using the verification data to determine whether the second ciphertext corresponds to the first data; and

A determining unit, configured to, in the case of determining that the second ciphertext corresponds to the first data, determine that the second ciphertext is used as the input of the secure multi-party computation protocol.

In one embodiment, in the apparatus for obtaining the input of the secure multi-party computation protocol, the verification data is obtained by storing the first ciphertext and the digital signature of the authoritative authority on the first ciphertext. the account book position, wherein the first ciphertext obtained by the method executed on the second server side is stored in the account book position,

Wherein, the verification unit further includes:

an obtaining subunit, configured to obtain the first ciphertext through the account book location; and

The determining subunit is configured to determine whether the second ciphertext is the same as the first ciphertext.

In one embodiment, in the device for obtaining the input of the secure multi-party computation protocol, the verification data is stored by storing the hash value of the first ciphertext and the authority's verification of the first ciphertext. The ledger position of the digital signature of the hash value of the ledger, where the hash value of the first ciphertext generated by the second server based on the ciphertext is stored in the ledger position,

Wherein, the verification unit includes:

by obtaining a subunit, configured to obtain the hash value of the first ciphertext through the account book location; and

The determining subunit is configured to determine whether the second ciphertext matches the hash value.

In one embodiment, in the device for obtaining the input of a secure multi-party computation protocol, the verification data is a digital signature of the first ciphertext by the authority,

Wherein, the verification unit further includes:

The determining subunit is configured to determine whether the second ciphertext matches the digital signature.

Another aspect of the present specification provides a device for obtaining input of a secure multi-party computation protocol, where participants of the secure multi-party computation protocol include a first server and a third server, and the first server is a server of a first object end, the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in a second server end, and the second server end is the server end of an authoritative organization, The apparatus is implemented on the third server, including:

a receiving unit, configured to receive, from the first server, the location of the ledger that stores the first ciphertext and the digital signature of the authoritative organization on the first ciphertext; and

The obtaining unit is configured to obtain the first ciphertext from the ledger position as an input of the secure multi-party computation protocol.

Another aspect of the present specification provides a device for obtaining input of a secure multi-party computation protocol, where participants of the secure multi-party computation protocol include a first server and a third server, and the first server is a server of a first object end, the secure multi-party computation protocol performs computation based on first data of the first object, wherein the first data is stored in the first server end, and the apparatus implements the third server end ,include:

a receiving unit, configured to receive, from the first server, the ciphertext and the account book location obtained by the method executed on the first server;

a verification unit configured to verify the ciphertext using the ledger location to determine whether the ciphertext corresponds to the first data; and

The determining unit is configured to, in the case of determining that the ciphertext corresponds to the first data, determine that the ciphertext is used as the input of the secure multi-party computation protocol.

Another aspect of the present specification provides a device for obtaining input of a secure multi-party computation protocol, where participants of the secure multi-party computation protocol include a first server and a third server, and the first server is a server of a first object end, the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the first server end, the apparatus is implemented at the third server end, including :

a receiving unit configured to receive, from the first server, the account book location obtained by the method executed on the first server; and

An obtaining unit, configured to obtain the ciphertext from the ledger location as an input of the secure multi-party computation protocol.

Another aspect of the present specification provides a computing device, including a memory and a processor, characterized in that, executable code is stored in the memory, and when the processor executes the executable code, any one of the above acquisition security is implemented A method of input to a multiparty computation protocol.

In this scheme, through the endorsement of homomorphic encrypted ciphertext, combined with the use of multi-party secure computing protocol, the contradiction between data privacy and data credibility is solved, and the use of powerful zero-knowledge proof technology is avoided. expensive computation and storage consumption. In addition, the present invention can solve the data falsification problem of using multi-prover data for evaluation.

Description of drawings

By describing the embodiments of the present specification in conjunction with the accompanying drawings, the embodiments of the present specification can be made clearer:

FIG. 1 shows a schematic diagram of a scenario of secure multi-party computing according to an embodiment of the present specification;

FIG. 2 shows a flowchart of a method for obtaining input of a secure multi-party computation protocol according to an embodiment of the present specification;

3 shows a flowchart of a method for obtaining input of a secure multi-party computation protocol according to another embodiment of the present specification;

FIG. 4 shows a flowchart of a method for obtaining input of a secure multi-party computation protocol according to another embodiment of the present specification;

FIG. 5 shows a flowchart of a method for obtaining the input of a secure multi-party computation protocol according to another embodiment of the present specification;

FIG. 6 shows a flowchart of a method for obtaining input of a secure multi-party computation protocol according to another embodiment of the present specification;

7 illustrates a method for obtaining input of a secure multi-party computation protocol according to another embodiment of the specification;

FIG. 8 shows a method for obtaining the input of a secure multi-party computation protocol according to another embodiment of the present specification;

FIG. 9 shows a method for obtaining the input of a secure multi-party computation protocol according to another embodiment of the present specification;

FIG. 10 shows a method for obtaining input of a secure multi-party computation protocol according to another embodiment of the present specification;

FIG. 11 shows a sequence diagram of a method according to an embodiment of the present specification;

FIG. 12 shows an apparatus 1200 for obtaining an input of a secure multi-party computation protocol according to an embodiment of the present specification;

FIG. 13 shows an apparatus 1300 for obtaining an input of a secure multi-party computation protocol according to another embodiment of the present specification;

FIG. 14 shows an apparatus 1400 for obtaining an input of a secure multi-party computation protocol according to another embodiment of the present specification;

FIG. 15 shows an apparatus 1500 for obtaining an input of a secure multi-party computation protocol according to another embodiment of the present specification;

FIG. 16 shows an apparatus 1600 for obtaining an input of a secure multi-party computation protocol according to another embodiment of the present specification;

FIG. 17 shows an apparatus 1700 for obtaining an input of a secure multi-party computation protocol according to another embodiment of the present specification;

FIG. 18 shows an apparatus 1800 for obtaining an input of a secure multi-party computation protocol according to another embodiment of the present specification;

FIG. 19 shows an apparatus 1900 for obtaining input of a secure multi-party computation protocol according to another embodiment of the present specification; and

FIG. 20 shows an apparatus 2000 for obtaining an input of a secure multi-party computation protocol according to another embodiment of the present specification.

Detailed ways

The embodiments of the present specification will be described below with reference to the accompanying drawings.

FIG. 1 shows a schematic diagram of a scenario of secure multi-party computation according to an embodiment of the present specification. As shown in FIG. 1 , the participants in the secure multi-party computation include a first server 11 and a third server 13 , the first server 11 is the prover server, and the prover is, for example, an individual, an enterprise, an organization, etc., and the third server The terminal 13 is the server side of the verifier, and the verifier can be an individual, an enterprise, or an organization that provides services to the prover. This scenario also includes a second server end 12, which is, for example, a server end of an authoritative institution such as a bank, a tax bureau, etc., in which the data of the prover is stored. Before the first server end 11 and the third server end 13 execute the secure multi-party computation protocol (MPC protocol), first, the first server end 11 sends a data request to the second server end 12, and the data request includes a request for the specific data of the prover. A request for ciphertext, a request for an endorsement certificate for specific data of the prover, etc. After receiving the above data request, the second server encrypts the specific data using the homomorphic encryption public key of the prover provided in advance by the prover to generate a homomorphic encrypted ciphertext, and generates a verification based on the homomorphic encrypted ciphertext data, the verification data is used to prove whether the ciphertext to be verified corresponds to the specific data. Then, the second server sends the ciphertext and verification data to the first server.

The first server 11 sends the received ciphertext and verification data to the third server 13 . The third server 13 verifies the ciphertext with the verification data, and when determining that the ciphertext corresponds to the specific data, determines that the ciphertext is the input of the secure multi-party computation protocol, and when determining that the ciphertext corresponds to the specific data When the data does not correspond, the MPC protocol is terminated.

The scenario of secure multi-party computation shown in FIG. 1 is only schematic, and the scenario of the embodiment of this specification is not limited to that shown in FIG. 1 . For example, the first server 11 can generate the ciphertext of the first data by itself, without receiving the ciphertext from the second server. For another example, the third server side can download the trusted ciphertext from the blockchain itself without receiving the ciphertext from the first server side. In addition, secure multi-party computation is not limited to two parties, but can include any number of parties. The prover can also obtain endorsement certificates from multiple endorsers. In addition, the prover can itself be the endorser, that is, the prover can also be the verifier if he endorses himself.

FIG. 2 shows a method for obtaining input of a secure multi-party computation protocol according to an embodiment of the present specification. The participants of the secure multi-party computation protocol include a first server end, the first server end is the server end of the first object, and the secure multi-party computation protocol performs computation based on the first data of the first object, wherein, The first data is stored in a second server side, which is a server side of an authority. The method is executed on the second server, including:

In step S202, a data request about the first data is received from the first server;

In step S204, based on the data request, perform homomorphic encryption on the first data by using the public key previously received from the first server to generate a first ciphertext, wherein the public key is the the homomorphic encryption public key of the first object;

In step S206, verification data is obtained based on the first ciphertext, and the verification data is used to verify whether the ciphertext to be verified corresponds to the first data; and

In step S208, the verification data is sent to the first server.

First, in step S202, a data request for the first data is received from the first server. For example, the first server end is a server end of an individual or an enterprise, which executes the PMC protocol with a third server end as shown in FIG. The first server and the third server execute the MPC protocol, so that the third server obtains the evaluation result of the first object (the individual or enterprise), while protecting the privacy of the first object relative to the third server data. The second server side is, for example, a server side of a bank, which stores the data of the first object, such as age, gender, deposit, income and so on. The data request specifies the data to be processed (ie, the first data). For example, the first data is the deposit of the first object, and the first server side specifies the deposit data in the data request. The data request may further include designation of an encryption processing method for the data, that is, designation to perform homomorphic encryption on the data through the public key of the first object. In addition, the data request may further include specification of the content to be sent back by the second server, for example, specifying the ciphertext of the data and the verification data of the ciphertext, or the verification data of the ciphertext and many more.

In step S204, based on the data request, perform homomorphic encryption on the first data by using the public key previously received from the first server to generate a first ciphertext, wherein the public key is the The homomorphic encryption public key of the first object. After the specific encryption of the first data is determined according to the data request, the second server obtains the first data and the public key of the first object from its own storage unit, and uses the public key of the first object to homomorphize the first data encryption to obtain the first ciphertext. Here, the homomorphic encryption public key and private key pair of the first object is pre-generated by the first server, and after generating the public-private key pair, the first server sends the public key to the second server, for implementing the method according to the embodiment of the present specification.

In one embodiment, the first server side also stores the first data. The first server performs homomorphic encryption on the first data by using its own homomorphic encryption public key, the first data, and a locally generated random number to obtain the second ciphertext. Therefore, when the first server side sends the data request to the second server side, the random number is included in the data request. Therefore, the second server can perform homomorphic encryption on the first data by using the public key and the random number received from the first server in advance, so as to generate the first ciphertext. That is, by sending the random number, it is ensured that the first ciphertext generated on the second server side is consistent with the second ciphertext generated on the first server side, so as to be used for executing the subsequent method.

In step S206, verification data is obtained based on the first ciphertext, and the verification data is used to verify whether the ciphertext to be verified corresponds to the first data.

In one embodiment, the verification data is a ledger location in the blockchain where the first ciphertext is certified by the authority. For example, after generating the first ciphertext, the second server generates a digital signature for the first ciphertext by an authority, and stores the first ciphertext and the digital signature in the blockchain. Specifically, the second server performs computation on the first ciphertext by using the private key of the authority, so as to generate encrypted data, which is used as the digital signature of the authority on the first ciphertext. Through the digital signature of the authoritative organization, it shows the endorsement certificate of the authoritative organization for the following content: the first ciphertext is the ciphertext obtained by performing homomorphic encryption on the first data with the public key of the first server. In addition, a consensus is reached by verifying the digital signature of the authority by other nodes in the blockchain with the public key of the authority, and storing the first ciphertext and digital signature in the blockchain, ensuring the first The ciphertext is not tampered with and the integrity, at the same time, the authenticity of the digital signature is guaranteed. Therefore, by obtaining the location of the ledger, the first ciphertext can be obtained from this location, and by comparing the first ciphertext with the ciphertext to be verified, it can be determined whether the ciphertext to be verified is the same as the ciphertext to be verified. The first data corresponds. That is, the location of the ledger can be used as verification data to verify whether the ciphertext to be verified corresponds to the first data.

Wherein, the second server can also store the hash value of the first ciphertext and the digital signature of the authoritative organization on the hash value in the blockchain, so as to obtain the storage in the blockchain. Ledger location of the hash value. Similarly, the authority has endorsed the hash value through its digital signature, that is, endorsed its corresponding first ciphertext. Therefore, by obtaining the position of the account book, the hash value of the first ciphertext can be obtained from the position, and by comparing the hash value of the ciphertext to be verified with the hash value of the first ciphertext, it can be determined Whether the ciphertext to be verified corresponds to the first data.

In one embodiment, the verification data is a digital signature of the first ciphertext by the authority generated by the second server. Specifically, after generating the first ciphertext as described above, the second server uses the private key of the authority to calculate the first ciphertext, so as to generate encrypted data as the first ciphertext of the authority. digital signature. The digital signature can be verified by the public key of the authoritative organization, and can ensure the immutability and integrity of the first ciphertext, which reflects the endorsement certificate of the authoritative organization on the first ciphertext. Therefore, by obtaining the digital signature and using the public key of the authority, it is verified whether the ciphertext to be verified matches the digital signature, so that it can be determined whether the ciphertext to be verified corresponds to the first data.

In step S208, the verification data is sent to the first server.

In one embodiment, for example, as described in step S204 above, the first server generates the second ciphertext locally, so the second server only needs to send the verification data to the first server , for use in subsequent methods. In another embodiment, after the second server generates the first ciphertext, the random number generated by the second server is sent to the first server, so that the first server can use the random number and the locally stored first ciphertext. One data, the first ciphertext corresponding to the first data is generated locally, that is, the second server needs to send the verification data and the random number used to generate the first ciphertext to the first server . In another embodiment, the second server sends the first ciphertext and the verification data to the first server for use in a subsequent method.

FIG. 3 shows a flowchart of a method for obtaining input of a secure multi-party computation protocol according to another embodiment of the present specification. The participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, and the secure multi-party computation protocol is based on the first data of the first object A calculation is performed, wherein the first data is stored in a second server side, the second server side being a server side of an authority. The method is executed on the first server, and includes the following steps S302-S306.

In step S302, a data request for the first data is sent to the second server. For a specific description of the data request in this step, reference may be made to the above description of step S202 in FIG. 2 , which will not be repeated here.

In step S304, a second ciphertext corresponding to the first data is obtained, wherein the second ciphertext is a homomorphically encrypted ciphertext obtained by using the pre-generated public key of the first object.

On the first server side, a pair of public and private keys of the first object for performing homomorphic encryption on data is pre-generated. In addition, the first server sends the public key therein to the second server in advance, so as to be used for implementing the method of this embodiment.

In one embodiment, the first ciphertext is received from the second server as the second ciphertext. The first ciphertext is generated by the second server by performing homomorphic encryption on the first data with the public key received from the first server in advance.

In one embodiment, the first server locally stores the first data. The first server locally performs homomorphic encryption on the first data by using the public key and the random number to obtain the second ciphertext. In this case, the random number is included in the data request for the first data, so that the second server can generate the first ciphertext according to the public key and the random number. Therefore, the first ciphertext and the second ciphertext are the same ciphertext.

In another embodiment, the first server locally stores the first data. After generating the first ciphertext by using the public key of the first object and the second random number locally generated by the second server, the second server sends the second random number to the first server. Thus, the first server locally generates the second ciphertext using the public key and the second random number.

In step S306, the verification data obtained by the method shown in FIG. 2 is received from the second server. As described above, the verification data obtained by the method executed on the second server side includes: the location of the ledger in the blockchain where the first ciphertext is certified, and the authoritative organization's verification of the first ciphertext. digital signature of the text.

In step S308, the second ciphertext and the verification data are sent to the third server. By sending the second ciphertext and the verification data to the third server, the third server can use the verification data to verify the second ciphertext as described above to determine whether the second ciphertext corresponds to the first data. Therefore, in the case that the second ciphertext corresponds to the first data, it can be determined that the second ciphertext is used as the input of the MPC protocol. That is, the second ciphertext is a trusted input, corresponding to the real data of the first object.

FIG. 4 shows a flowchart of a method for obtaining input of a secure multi-party computation protocol according to another embodiment of the present specification. The participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, and the secure multi-party computation protocol is based on the first data of the first object A calculation is performed, wherein the first data is stored in a second server side, the second server side being a server side of an authority. The method is executed on the first server side, and includes the following steps S402-S406.

In step S402, a data request for the first data is sent to the second server. For a specific description of the data request in this step, reference may be made to the above description of step S202 in FIG. 2 , which will not be repeated here.

In step S404, the account book position in the blockchain obtained by the method shown in FIG. 2 is obtained from the second server, wherein the first ciphertext corresponding to the first data is stored in the account book position , and the digital signature of the authority on the first ciphertext. Referring to the above description of step S206 in FIG. 2 , the first ciphertext is obtained by encrypting the local first data by the second server, a digital signature is generated for the first ciphertext, and the first ciphertext and digital The signature is stored in the blockchain, that is, the second server end endorses the first ciphertext, and the first ciphertext stored in the ledger location is the trusted ciphertext corresponding to the first data.

In step S406, the account book location is sent to the third server. By sending the location of the ledger to the third server, the third server can directly download the trusted ciphertext corresponding to the first data from the location of the ledger, so that it can be used as the input of the MPC protocol.

FIG. 5 shows a flowchart of a method for obtaining input of a secure multi-party computation protocol according to another embodiment of the present specification. The participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, and the secure multi-party computation protocol is based on the first data of the first object Calculation. Wherein, the first data is stored in the first server. This embodiment is different from the previous embodiment in that the first object is not only the object to be evaluated, but also an authoritative institution, which endorses itself. For example, the first server side is the server side of the bank, that is, the first server side is also the second server side at the same time. The method is executed on the first server side, and includes the following steps S502-S506.

In step S502, a ciphertext corresponding to the first data is obtained by performing homomorphic encryption on the first data by using the pre-generated public key of the first object. That is, the first server uses the homomorphic encryption public key of the first object to perform homomorphic encryption on the local first data, thereby locally generating the ciphertext corresponding to the first data.

In step S504, by depositing the ciphertext in the blockchain, the location of the ledger where the ciphertext is stored in the blockchain is obtained. Here, similar to the corresponding description of step S206 in FIG. 2 above, the location of the ledger here is a case of verifying data in step S206 above. The difference is that in

In the embodiment shown in FIG. 2 , the ciphertext is stored in the blockchain by the second server. In this embodiment, since the first object is both the object to be evaluated and the authority, that is, the first server side simultaneously acts as the second server side. Therefore, in this embodiment, the ciphertext is authenticated by the first server. For the description of the specific process of depositing the certificate, reference may be made to the description of step S206 above, which will not be repeated here.

In step S506, the ciphertext and the location of the ledger are sent to the third server. For the specific implementation of this step, reference may be made to the above description of step S308 in FIG. 3 , which will not be repeated here.

In this embodiment, by storing the ciphertext in the blockchain by the first server, the first object endorses itself. Among them, the consensus verification of the data ciphertext of the first object can be performed through consensus in the blockchain, and the tamper-proof modification of the ciphertext can be ensured, thereby increasing the credibility of the ciphertext.

FIG. 6 illustrates a method for obtaining input of a secure multi-party computation protocol according to another embodiment of the present specification. The participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, and the secure multi-party computation protocol is based on the first data of the first object A calculation is performed, wherein the first data is stored in the first server side. This embodiment is similar to the embodiment shown in FIG. 5 , that is, the first object is both an object to be evaluated and an authority, that is, the first server side is also the second server side. The difference is that in this embodiment, similar to the embodiment shown in FIG. 3 , the third server obtains the ciphertext from the location of the ledger. The method is executed on the first server side, and includes the following steps S602-S606.

In step S602, a ciphertext corresponding to the first data is obtained by performing homomorphic encryption on the first data by using the pre-generated public key of the first object. For the specific implementation of this step, reference may be made to the above description of step S502 in FIG. 5 , which will not be repeated here.

In step S604, by storing the ciphertext and the digital signature of the first object on the ciphertext in the blockchain, the location of the ledger where the ciphertext and the digital signature are stored in the blockchain is obtained, The digital signature is generated by the first server. Here, the first server stores the ciphertext and the digital signature of the first object into the blockchain, so that the ciphertext and its digital signature are verified by consensus in the blockchain, And guarantee the tamper-proof of the ciphertext.

In step S606, the account book location is sent to the third server. By sending the location of the ledger to the third server, the third server can download the consensus ciphertext from the blockchain, thereby ensuring the credibility of the ciphertext.

Figure 7 illustrates a method of obtaining input to a secure multi-party computation protocol according to another embodiment of the specification. The participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, and the secure multi-party computation protocol is based on the first data of the first object A calculation is performed, wherein the first data is stored in a second server side, the second server side being a server side of an authority. The method is executed on the third server, and includes the following steps S702-S706.

First, in step S702, the second ciphertext and verification data obtained by the method shown in FIG. 3 are received from the first server. Here, for the specific description of the second ciphertext and the verification data, reference may be made to the above description of steps S304 and S306 in FIG. 3 , which will not be repeated here.

In step S704, the second ciphertext is verified using the verification data to determine whether the second ciphertext corresponds to the first data.

In one embodiment, the verification data is a ledger location where the first ciphertext is stored. In this case, verifying the second ciphertext using the verification data includes: obtaining the first ciphertext through the ledger location; and determining whether the second ciphertext is the same as the first ciphertext . In the case where the second ciphertext is the same as the first ciphertext, it may be determined that the second ciphertext corresponds to the first data.

In one embodiment, the verification data is a ledger location where the hash value of the first ciphertext is stored. In this case, verifying the second ciphertext using the verification data includes: obtaining a hash value of the first ciphertext through the ledger position; and determining the second ciphertext and the hash Whether the values match, that is, it is determined whether the hash value of the second ciphertext is the same as the hash value of the first ciphertext. In the case where the second ciphertext matches the hash value, it may be determined that the second ciphertext corresponds to the first data.

In one embodiment, the verification data is a digital signature of the first ciphertext by the above-mentioned authority, in this case, using the verification data to verify the second ciphertext comprises: determining the second ciphertext Whether the text matches the digital signature. Specifically, the third server decrypts the digital signature using the public key of the authority pre-obtained from the second server to obtain the first message digest, and uses the hash function pre-obtained from the second server to extract the first message digest from the digital signature. The second ciphertext calculates the second message digest. If the second message digest is the same as the first message digest, it can be determined that the second ciphertext matches the digital signature, that is, it can be determined that the second ciphertext corresponds to the first data.

In step S706, in the case where it is determined that the second ciphertext corresponds to the first data, it is determined that the second ciphertext is used as the input of the secure multi-party computation protocol. In the case where it is determined that the second ciphertext corresponds to the first data, that is, it is determined that the second ciphertext is the ciphertext obtained by performing homomorphic encryption on the first data with the public key of the first object, so it can be used in the MPC protocol , and make sure to get real and credible results through the MPC protocol.

Fig. 8 shows a method for obtaining input of a secure multi-party computation protocol according to another embodiment of the present specification, the participants of the secure multi-party computation protocol include a first server end and a third server end, the first server The end is the server end of the first object, and the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the second server end, and the second server end is the server side of the authority. The method is executed on the third server and includes the following steps S802-S804.

First, in step S802, the location of the ledger where the first ciphertext is stored in the blockchain is received from the first server.

In step S804, the first ciphertext is obtained from the ledger location as the input of the secure multi-party computation protocol.

This embodiment is different from the embodiment shown in FIG. 7 in that, in this embodiment, the first ciphertext is directly downloaded and obtained from the blockchain ledger as the second ciphertext in the embodiment shown in FIG. The second ciphertext is received from the first server. Since the first ciphertext is the ciphertext corresponding to the first data that has been endorsed and certified by an authority, and is obtained by performing homomorphic encryption with the public key of the first object, it can be used by the first server to communicate with MPC protocol between the third server, and can ensure the acquisition of real and credible calculation results.

FIG. 9 illustrates a method for obtaining input of a secure multi-party computation protocol according to another embodiment of the present specification. The participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, and the secure multi-party computation protocol is based on the first data of the first object A calculation is performed, wherein the first data is stored in the first server side. The method is executed on the third server, and includes the following steps S902-S906.

First, in step S902, the ciphertext obtained by the method shown in FIG. 5 and the ledger position in the blockchain where the ciphertext is stored are received from the first server. For the specific description of the ciphertext and the location of the ledger, reference may be made to the above description of steps S502 and S504 in FIG. 5 , which will not be repeated here.

In step S904, the ciphertext is verified using the ledger location to determine whether the ciphertext corresponds to the first data. For the specific implementation of this step, reference may be made to the corresponding description in the description of step S704 in FIG. 7 above, which will not be repeated here.

In step S906, when it is determined that the ciphertext corresponds to the first data, it is determined that the ciphertext is used as the input of the secure multi-party computation protocol. For the specific implementation of this step, reference may be made to the above description of step S706 in FIG. 7 , which will not be repeated here.

The method shown in this embodiment is different from the method shown in FIG. 7 in that, in this embodiment, the first server end stores the ciphertext in the blockchain, so that the first object endorses itself. Among them, the consensus verification of the data ciphertext of the first object can be performed through consensus in the blockchain, and the tamper-proof modification of the ciphertext can be ensured, thereby increasing the credibility of the ciphertext.

FIG. 10 shows a method for obtaining input of a secure multi-party computation protocol according to another embodiment of the present specification. The participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, and the secure multi-party computation protocol is based on the first data of the first object A calculation is performed, wherein the first data is stored in the first server side. The method is executed on the third server, and includes the following steps S1002-S1004.

First, in step S1002, the location of the ledger where the ciphertext is stored in the blockchain obtained by the method shown in FIG. 6 is received from the first server.

In step S1004, the ciphertext is obtained from the location of the ledger as the input of the secure multi-party computation protocol.

This embodiment is different from the embodiment shown in FIG. 9 in that, in this embodiment, the ciphertext is directly downloaded and obtained from the blockchain ledger, so that it is not necessary to receive the ciphertext from the first server. Since the ciphertext is the ciphertext corresponding to the first data that has been endorsed and certified by an authority, and is obtained by performing homomorphic encryption with the public key of the first object, it can be used by the first server to communicate with MPC protocol between the third server, and can ensure the acquisition of real and credible calculation results.

FIG. 11 shows a sequence diagram of a method according to an embodiment of the present specification. Figure 11 includes part I and part II, where part I corresponds to the situation where the first server side obtains the verification data from the second server side of the authority, and part II corresponds to the first server side preparing the verification data by itself (ie without the need for a second server side of the authority). In Part I, first, the first server sends a data request to the second server, the second server prepares the first ciphertext and verification data according to the data request, and sends the verification data to the first server, optionally , and also send the first ciphertext to the first server. Then, the first server sends the second ciphertext (optional) and verification data to the third server. Therefore, the third server verifies the second ciphertext with the verification data to determine whether the second ciphertext is used as the input of the MPC protocol. Here, the second ciphertext may be the first ciphertext obtained from the second server, or may be the ciphertext generated locally by using the local public key and the first data. Optionally, the first server only sends the verification data to the third server, and the verification data is the ledger position where the authoritative organization stores the first ciphertext in the blockchain, so that the third server can directly The first ciphertext is downloaded from the ledger location for use in the MPC protocol.

In part II, the first server locally generates the homomorphically encrypted ciphertext of the first data, and stores the ciphertext in the blockchain to obtain the location of the ledger where the ciphertext is stored in the blockchain as the Describe the verification data. Then, the first server sends the ciphertext (optional) and the location of the ledger to the third server. Therefore, the third server verifies the ciphertext through the location of the ledger to determine whether the ciphertext is used as the input of the MPC protocol. Optionally, the first server end only sends the account book location to the third server end, so that the third server end can directly download the ciphertext from the account book location as the input of the MPC protocol.

In the above-mentioned embodiments, it is shown that the input of the MPC protocol is obtained between the first server, the second server and the third server, or between the first server and the third server. The method, wherein the participants of the MPC protocol include a first server end and a third server end. However, the above-described embodiments do not limit the scope of the present invention.

In one embodiment, the first server side may obtain authentication data and ciphertext (optional) from the servers of two or more authoritative institutions (such as banks and tax bureaus), in this case, the first server side may communicate with The server side of each authority implements the method shown in FIG. 3 to obtain the input of the MPC protocol respectively.

In one embodiment, the methods executed by the first server side and the third server side are interchangeable, that is, the prover of the first server can also be the verifier, and the verifier of the third server can also be the prover, for example The two cooperating parties evaluate each other, therefore, the method according to the above embodiment will be executed twice between them, once with one party as the prover and the other as the verifier, and the other time the two parties switch roles. The execution of the two methods can be performed simultaneously or sequentially. The method performed twice may be the same or different (for example, the method shown in FIG. 3 is performed once, and the method shown in FIG. 4 is performed once).

In one embodiment, the third server (verifier) performs ciphertext verification on two or more prover servers, so as to obtain the input of the MPC protocol from each prover respectively. In this case, the third server and each of the prover servers respectively execute the method shown in FIG. 3 to obtain the input of the MPC protocol respectively.

In one embodiment, the first server end (the prover) provides the ciphertext of the first data and the verification data thereof to the plurality of verifier server ends. In this case, the first server can send the ciphertext and the verification data obtained by the method shown in the above embodiment to each verifier server, so as to obtain the MPC protocol corresponding to each verifier server respectively. enter.

FIG. 12 shows an apparatus 1200 for obtaining an input of a secure multi-party computation protocol according to an embodiment of the present specification. Participants in the secure multi-party computation protocol include a first server, and the first server is a first object's On the server side, the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the second server side, and the second server side is the server side of the authoritative organization , the apparatus is implemented on the second server, including:

a receiving unit 121, configured to receive a data request for the first data from the first server;

The generating unit 122 is configured to, based on the data request, perform homomorphic encryption on the first data by using the public key previously received from the first server to generate a first ciphertext, wherein the public key is a homomorphic encryption public key for the first object;

The obtaining unit 123 is configured to obtain verification data based on the first ciphertext, where the verification data is used to verify whether the ciphertext to be verified corresponds to the first data; and

The sending unit 124 is configured to send the verification data to the first server.

In one embodiment, in the apparatus for obtaining the input of the secure multi-party computation protocol, the data request includes a random number for performing homomorphic encryption on the first data, and the generating unit is further configured to , performing homomorphic encryption on the first data by using the public key and the random number received from the first server in advance to generate a first ciphertext.

In one embodiment, in the apparatus for obtaining the input of the secure multi-party computation protocol, the sending unit is further configured to send the verification data and the first ciphertext to the first server.

In one embodiment, in the device for obtaining the input of the secure multi-party computation protocol, the obtaining unit is further configured to obtain the first ciphertext in the blockchain by storing the certificate in the blockchain. The location of the ledger where the first ciphertext is stored is used as the verification data.

FIG. 13 shows an apparatus 1300 for obtaining input of a secure multi-party computation protocol according to an embodiment of the present specification. Participants in the secure multi-party computation protocol include a first server and a third server. The first server is the server side of the first object, and the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the second server side, and the second server side is The server side of the authority, the apparatus is implemented on the first server side, including:

a first sending unit 131, configured to send a data request for the first data to the second server;

The obtaining unit 132 is configured to obtain a second ciphertext corresponding to the first data, wherein the second ciphertext is a homomorphically encrypted ciphertext obtained by using the pre-generated public key of the first object;

The receiving unit 133 is configured to receive, from the second server, the verification data obtained according to the method shown in FIG. 2; and

The second sending unit 134 is configured to send the second ciphertext and the verification data to the third server.

In one embodiment, in the apparatus for acquiring the input of the secure multi-party computation protocol, the acquiring unit is further configured to receive the first ciphertext generated by the method shown in FIG. 2 from the second server side as the second ciphertext.

In one embodiment, in the device for obtaining the input of the secure multi-party computation protocol, the first server stores the first data, and wherein the obtaining unit is further configured to locally pass the Homomorphically encrypt the first data with the public key and a locally generated random number to obtain the second ciphertext, wherein the random number is included in the data request for the first data.

FIG. 14 shows an apparatus 1400 for obtaining an input of a secure multi-party computation protocol according to an embodiment of the present specification. Participants in the secure multi-party computation protocol include a first server and a third server. The first server is the server side of the first object, and the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the second server side, and the second server side is The server side of the authority, the apparatus is executed on the first server side, including:

a first sending unit 141, configured to send a data request for the first data to the second server;

a receiving unit 142, configured to receive, from the second server, the location of the ledger that stores the first ciphertext and the digital signature of the authoritative organization on the first ciphertext; and

The second sending unit 143 is configured to send the account book location to the third server.

FIG. 15 shows an apparatus 1500 for obtaining input of a secure multi-party computation protocol according to an embodiment of the present specification. Participants in the secure multi-party computation protocol include a first server and a third server. The first server is the server side of the first object, and the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the first server side, and the device is located in the The first server-side execution includes:

The encryption unit 151 is configured to perform homomorphic encryption on the first data by using the pre-generated public key of the first object to obtain a ciphertext corresponding to the first data;

The certificate depositing unit 152 is configured to, by depositing the ciphertext in the blockchain, obtain the location of the ledger where the ciphertext is stored in the blockchain; and

The sending unit 153 is configured to send the ciphertext and the location of the ledger to the third server.

FIG. 16 shows an apparatus 1600 for obtaining input of a secure multi-party computation protocol according to an embodiment of the present specification. Participants in the secure multi-party computation protocol include a first server and a third server, and the first server is the server side of the first object, and the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the first server side, and the device is located in the The first server-side implementation described above includes:

The encryption unit 161 is configured to perform homomorphic encryption on the first data by using the pre-generated public key of the first object to obtain a ciphertext corresponding to the first data;

The depositing unit 162 is configured to, by depositing the ciphertext and the digital signature of the first object on the ciphertext in the blockchain, obtain the ciphertext and the digital number stored in the blockchain a signed ledger location, wherein the digital signature is generated by the first server side; and

The sending unit 163 is configured to send the location of the account book to the third server.

FIG. 17 shows an apparatus 1700 for obtaining an input of a secure multi-party computation protocol according to an embodiment of the present specification. Participants in the secure multi-party computation protocol include a first server and a third server. The first server is the server side of the first object, and the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the second server side, and the second server side is The server side of the authority, the apparatus is implemented on the third server side, including:

The receiving unit 171 is configured to receive the second ciphertext and the verification data obtained by the method shown in FIG. 3 from the first server;

a verification unit 172, configured to verify the second ciphertext using the verification data to determine whether the second ciphertext corresponds to the first data; and

The determining unit 173 is configured to, in the case of determining that the second ciphertext corresponds to the first data, determine that the second ciphertext is used as the input of the secure multi-party computation protocol.

In one embodiment, in the device for obtaining the input of a secure multi-party computation protocol, the verification data is the first ciphertext and the digital signature of the authoritative authority on the first ciphertext. Ledger position, wherein the first ciphertext obtained by the method shown in FIG. 2 is stored in the account book position,

Wherein, the verification unit includes:

a first obtaining subunit 1721, configured to obtain the first ciphertext through the account book location; and

The first determination subunit 1722 is configured to determine whether the second ciphertext is the same as the first ciphertext.

In one embodiment, in the device for obtaining the input of the secure multi-party computation protocol, the verification data is a hash value of the first ciphertext and a hash value of the first ciphertext stored by the authority. the ledger location of the digital signature of the hash value,

Wherein, the verification unit further includes:

The second obtaining subunit 1723 is configured to obtain the hash value of the first ciphertext through the location of the ledger; and

The second determination subunit 1724 is configured to determine whether the second ciphertext matches the hash value.

In one embodiment, in the device for obtaining the input of a secure multi-party computation protocol, the verification data is a digital signature of the first ciphertext by the authority,

Wherein, the verification unit further includes:

The third determination subunit 1725 is configured to determine whether the second ciphertext matches the digital signature.

FIG. 18 shows an apparatus 1800 for obtaining an input of a secure multi-party computation protocol according to an embodiment of the present specification. Participants in the secure multi-party computation protocol include a first server and a third server. The first server is the server side of the first object, and the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the second server side, and the second server side is The server side of the authority, the apparatus is implemented on the third server side, including:

a receiving unit 181, configured to receive, from the first server, the location of the ledger where the first ciphertext and the digital signature of the authoritative organization on the first ciphertext are stored; and

The obtaining unit 182 is configured to obtain the first ciphertext from the location of the ledger as an input of the secure multi-party computation protocol.

FIG. 19 shows an apparatus 1900 for obtaining an input of a secure multi-party computation protocol according to an embodiment of the present specification. Participants in the secure multi-party computation protocol include a first server and a third server. The first server is the server side of the first object, and the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the first server side, and the device is located in the The third server-side implementation described above includes:

The receiving unit 191 is configured to receive the ciphertext and the account book location obtained by the method shown in FIG. 5 from the first server;

a verification unit 192 configured to verify the ciphertext using the ledger location to determine whether the ciphertext corresponds to the first data; and

The determining unit 193 is configured to, in the case of determining that the ciphertext corresponds to the first data, determine that the ciphertext is used as the input of the secure multi-party computation protocol.

FIG. 20 shows an apparatus 2000 for obtaining input of a secure multi-party computation protocol according to an embodiment of the present specification. Participants in the secure multi-party computation protocol include a first server end and a third server end, and the first server end It is the server side of the first object, and the secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the first server side, and the device is in the first object. Three server-side implementations, including:

a receiving unit 201, configured to receive the account book location obtained by the method shown in FIG. 6 from the first server; and

The obtaining unit 202 is configured to obtain the ciphertext from the location of the ledger as an input of the secure multi-party computation protocol.

Another aspect of the present specification provides a computing device, including a memory and a processor, characterized in that, executable code is stored in the memory, and when the processor executes the executable code, any one of the above acquisition security is implemented A method of input to a multiparty computation protocol.

In this scheme, through the endorsement of homomorphic encrypted ciphertext, combined with the use of multi-party secure computing protocol, the contradiction between data privacy and data credibility is solved, and the use of powerful zero-knowledge proof technology is avoided. expensive computation and storage consumption. In addition, the present invention can solve the data falsification problem of using multi-prover data for evaluation.

Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the various embodiments may be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, as for the system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and for related parts, please refer to the partial descriptions of the method embodiments.

The foregoing describes specific embodiments of the present specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that in the embodiments and still achieve desirable results. Additionally, the processes depicted in the figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Those of ordinary skill in the art should further realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software or a combination of the two, in order to clearly illustrate the hardware and software interchangeability, the components and steps of each example have been generally described in terms of functions in the above description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Persons of ordinary skill in the art may use different methods of implementing the described functionality for each particular application, but such implementations should not be considered beyond the scope of this application.

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be implemented in hardware, a software module executed by a processor, or a combination of the two. A software module can be placed in random access memory (RAM), internal memory, read only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other in the technical field. in any other known form of storage medium.

The specific embodiments described above further describe the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (35)

1. a method for obtaining the input of a secure multi-party computation protocol, the participant of the secure multi-party computation protocol comprises a first server end, the first server end is the server end of the first object, and the secure multi-party computation protocol is based on. The first data of the first object is calculated, wherein the first data is stored in the second server side, the second server side is the server side of the authoritative organization, and the method is performed on the second server side execution, including: receiving a data request for the first data from the first server; Based on the data request, perform homomorphic encryption on the first data by using the public key previously received from the first server to generate a first ciphertext, where the public key is the first object's Homomorphic encryption public key; By depositing the first ciphertext in the blockchain, the ledger position where the first ciphertext is stored in the blockchain is obtained as verification data, and the verification data is used to verify whether the first ciphertext matches the The first data corresponds, and in the case where it is determined that the first ciphertext corresponds to the first data, it is determined that the first ciphertext is used as the input of the secure multi-party computation protocol; and Send the verification data to the first server. 2. The method for obtaining the input of a secure multi-party computation protocol according to claim 1, wherein the data request includes a random number for performing homomorphic encryption on the first data, wherein the random number is obtained from the first data in advance. Homomorphically encrypting the first data with the public key received by the server to generate the first ciphertext includes: encrypting the first data with the public key and the random number received from the first server in advance Homomorphic encryption is performed to generate the first ciphertext. 3. The method for obtaining the input of a secure multi-party computation protocol according to claim 1, wherein sending the verification data to the first server comprises sending the verification data and the first ciphertext to a the first server side. 4. The method for obtaining the input of a secure multi-party computation protocol according to claim 1, wherein storing the first ciphertext in the blockchain comprises storing the first ciphertext in the ledger location and a digital signature of the first ciphertext by the authority, wherein the digital signature is generated by the second server. 5. The method for obtaining the input of a secure multi-party computation protocol according to claim 1, wherein depositing the first ciphertext in the blockchain comprises storing the first ciphertext in the ledger location The hash value of the first ciphertext, and the digital signature of the authority to the hash value of the first ciphertext, wherein the hash value of the first ciphertext is determined by the second server based on the first ciphertext. generated, the digital signature is generated by the second server. 6. A method for obtaining the input of a secure multi-party computation protocol, the participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, the The secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the second server side, the second server side is the server side of the authoritative organization, and the method is in The first server-side execution includes: sending a data request for the first data to the second server; obtaining a second ciphertext corresponding to the first data, wherein the second ciphertext is a homomorphically encrypted ciphertext obtained by using the pre-generated public key of the first object; Receive from the second server the verification data obtained by the method according to any one of claims 1-5; and Send the second ciphertext and the verification data to the third server. 7. The method for obtaining the input of a secure multi-party computation protocol according to claim 6, wherein obtaining the second ciphertext corresponding to the first data comprises: The first ciphertext generated by the method described above is used as the second ciphertext. 8. The method for obtaining the input of a secure multi-party computation protocol according to claim 6, wherein the first server side stores the first data, and wherein the second data corresponding to the first data is obtained The ciphertext includes performing homomorphic encryption on the first data locally by using the public key and a locally generated random number to obtain the second ciphertext, wherein in the data request for the first data Include the random number. 9. A method for obtaining the input of a secure multi-party computation protocol, the participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, the The secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the second server side, the second server side is the server side of the authoritative organization, and the method is in The first server-side execution includes: sending a data request for the first data to the second server; receiving the ledger location obtained by the method of claim 4 from the second server side; and Sending the ledger location to the third server. 10. A method for obtaining the input of a secure multi-party computation protocol, the participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, the The secure multi-party computation protocol performs computation based on first data of the first object, wherein the first data is stored in the first server, and the method is executed on the first server, including: Obtain the ciphertext corresponding to the first data by performing homomorphic encryption on the first data by using the pre-generated public key of the first object; By depositing the ciphertext in the blockchain, obtaining the location of the ledger where the ciphertext is stored in the blockchain; and sending the ciphertext and the location of the ledger to the third server, where the ciphertext and the location of the ledger are used to determine whether the ciphertext corresponds to the first data; and, after determining the In the case that the ciphertext corresponds to the first data, it is determined that the ciphertext is used as the input of the secure multi-party computation protocol. 11. A method for obtaining the input of a secure multi-party computation protocol, the participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, the The secure multi-party computation protocol performs computation based on first data of the first object, wherein the first data is stored in the first server, and the method is executed on the first server, including: Obtain the ciphertext corresponding to the first data by performing homomorphic encryption on the first data by using the pre-generated public key of the first object; By storing the ciphertext and the digital signature of the first object on the ciphertext in the blockchain, the location of the ledger where the ciphertext and the digital signature are stored in the blockchain is obtained, wherein the a digital signature is generated by the first server; and Sending the account book position to the third server, where the account book position is used to determine whether the ciphertext corresponds to the first data; and, after determining that the ciphertext corresponds to the first data In this case, it is determined that the ciphertext is used as the input of the secure multi-party computation protocol. 12. A method for obtaining the input of a secure multi-party computation protocol, the participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, the The secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the second server side, the second server side is the server side of the authoritative organization, and the method is in The third server-side execution includes: Receive the second ciphertext and the verification data obtained by the method according to claim 6 from the first server; verifying the second ciphertext using the verification data to determine whether the second ciphertext corresponds to the first data; and In the case where it is determined that the second ciphertext corresponds to the first data, it is determined that the second ciphertext is used as the input of the secure multi-party computation protocol. 13. The method of obtaining the input of a secure multi-party computation protocol according to claim 12, wherein said verification data is said ledger location obtained by the method according to claim 4, wherein said ledger location is stored There is the first ciphertext obtained by the method according to claim 1, Wherein, using the verification data to verify the second ciphertext includes: obtaining the first ciphertext through the ledger location; and It is determined whether the second ciphertext is the same as the first ciphertext. 14. The method for obtaining the input of a secure multi-party computation protocol according to claim 12, wherein the verification data is the account book location obtained by the method according to The hash value of the first ciphertext obtained by the method according to claim 5, Wherein, using the verification data to verify the second ciphertext includes: obtaining the hash value of the first ciphertext through the ledger location; and It is determined whether the second ciphertext matches the hash value. 15. A method for obtaining the input of a secure multi-party computation protocol, the participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, the The secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the second server side, the second server side is the server side of the authoritative organization, and the method is in The third server-side execution includes: receiving the ledger location obtained by the method of claim 4 from the first server side; and The first ciphertext is obtained from the ledger location as an input to the secure multi-party computation protocol. 16. A method for obtaining the input of a secure multi-party computation protocol, the participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, the The secure multi-party computation protocol performs computation based on first data of the first object, wherein the first data is stored in the first server, and the method is executed on the third server, including: Receive the ciphertext and the ledger location obtained by the method according to claim 10 from the first server; verifying the ciphertext using the ledger location to determine whether the ciphertext corresponds to the first data; and In the case where it is determined that the ciphertext corresponds to the first data, it is determined that the ciphertext is used as the input of the secure multi-party computation protocol. 17. A method for obtaining the input of a secure multi-party computation protocol, the participant of the secure multi-party computation protocol comprises a first server end and a third server end, the first server end is the server end of the first object, the described The secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the first server, and the method is executed on the third server, including: receiving the ledger location obtained by the method of claim 11 from the first server side; and The ciphertext is obtained from the ledger location as an input to the secure multi-party computation protocol. 18. A device for obtaining the input of a secure multi-party computation protocol, the participants of the secure multi-party computation protocol include a first server end, the first server end is the server end of the first object, and the secure multi-party computation protocol is based on. The first data of the first object is calculated, wherein the first data is stored in the second server side, the second server side is the server side of the authoritative organization, and the device is on the second server side side implementation, including: a receiving unit, configured to receive a data request for the first data from the first server; A generating unit, configured to, based on the data request, perform homomorphic encryption on the first data by using a public key previously received from the first server to generate a first ciphertext, wherein the public key is the homomorphic encryption public key of the first object; an obtaining unit, configured to, by depositing the first ciphertext in the blockchain, obtain the location of the ledger where the first ciphertext is stored in the blockchain as verification data, and the verification data is used for verification Whether the first ciphertext corresponds to the first data, in the case where it is determined that the first ciphertext corresponds to the first data, it is determined that the first ciphertext is used as the input of the secure multi-party computation protocol; as well as A sending unit, configured to send the verification data to the first server. 19. The device for obtaining the input of a secure multi-party computation protocol according to claim 18, wherein the data request includes a random number for performing homomorphic encryption on the first data, wherein the generating unit is further configured In order to generate a first ciphertext, the first data is homomorphically encrypted by using the public key and the random number received from the first server in advance. 20. The apparatus for obtaining the input of a secure multi-party computation protocol according to claim 18, wherein the sending unit is further configured to send the verification data and the first ciphertext to the first server. 21. The apparatus for obtaining the input of a secure multi-party computation protocol according to claim 18, wherein depositing the first ciphertext in the blockchain comprises storing the first ciphertext in the ledger location and a digital signature of the first ciphertext by the authority, wherein the digital signature is generated by the second server. 22. The apparatus for obtaining input of a secure multi-party computation protocol according to claim 18, wherein storing the first ciphertext in the blockchain comprises storing the first ciphertext in the ledger location The hash value of the first ciphertext, and the digital signature of the authority to the hash value of the first ciphertext, wherein the hash value of the first ciphertext is determined by the second server based on the first ciphertext. generated, the digital signature is generated by the second server. 23. A device for obtaining the input of a secure multi-party computation protocol, the participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, the The secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in a second server side, the second server side is a server side of an authority, and the device is in The first server-side implementation includes: a first sending unit, configured to send a data request for the first data to the second server; an obtaining unit, configured to obtain a second ciphertext corresponding to the first data, wherein the second ciphertext is a homomorphically encrypted ciphertext obtained by using a pre-generated public key of the first object; a receiving unit configured to receive, from the second server, the verification data obtained by the method according to any one of claims 1-5; and The second sending unit is configured to send the second ciphertext and the verification data to the third server. 24. The apparatus for obtaining the input of a secure multi-party computation protocol according to claim 23, wherein the obtaining unit is further configured to receive the generated data generated by the method according to claim 1 from the second server side The first ciphertext is used as the second ciphertext. 25. The device for obtaining the input of a secure multi-party computation protocol according to claim 23, wherein the first server side stores the first data, and wherein the obtaining unit is further configured to locally pass The first data is homomorphically encrypted with the public key and a locally generated random number, wherein the random number is included in the data request for the first data, to obtain the second ciphertext. 26. A device for obtaining the input of a secure multi-party computation protocol, the participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, the The secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in a second server side, the second server side is a server side of an authority, and the device is in The first server-side execution includes: a first sending unit, configured to send a data request for the first data to the second server; a receiving unit configured to receive, from the second server, the ledger location obtained by the method according to claim 4; and The second sending unit is configured to send the account book location to the third server. 27. A device for obtaining the input of a secure multi-party computation protocol, the participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, the The secure multi-party computation protocol performs computation based on first data of the first object, wherein the first data is stored in the first server, and the apparatus is executed on the first server, including: an encryption unit, configured to perform homomorphic encryption on the first data by using the pre-generated public key of the first object to obtain a ciphertext corresponding to the first data; a certificate depositing unit, configured to obtain the location of the ledger where the ciphertext is stored in the blockchain by depositing the ciphertext in the blockchain; and a sending unit, configured to send the ciphertext and the location of the ledger to the third server, where the ciphertext and the location of the ledger are used to determine whether the ciphertext corresponds to the first data; And, in the case where it is determined that the ciphertext corresponds to the first data, it is determined that the ciphertext is used as the input of the secure multi-party computation protocol. 28. A device for obtaining the input of a secure multi-party computation protocol, the participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, the The secure multi-party computation protocol performs computation based on first data of the first object, wherein the first data is stored in the first server, and the apparatus is implemented on the first server, including: an encryption unit, configured to perform homomorphic encryption on the first data by using the pre-generated public key of the first object to obtain a ciphertext corresponding to the first data; a depositing unit, configured to obtain the ciphertext and the digital signature stored in the blockchain by depositing the ciphertext and the digital signature of the first object on the ciphertext in the blockchain , where the digital signature is generated by the first server side; and a sending unit, configured to send the account book position to the third server, where the account book position is used to determine whether the ciphertext corresponds to the first data; In the case corresponding to the first data, it is determined that the ciphertext is used as the input of the secure multi-party computation protocol. 29. A device for obtaining the input of a secure multi-party computation protocol, the participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, the The secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in a second server side, the second server side is a server side of an authority, and the device is in The third server-side implementation includes: a receiving unit, configured to receive the second ciphertext and the verification data obtained by the method according to claim 6 from the first server; a verification unit configured to verify the second ciphertext using the verification data to determine whether the second ciphertext corresponds to the first data; and A determining unit, configured to, in the case of determining that the second ciphertext corresponds to the first data, determine that the second ciphertext is used as the input of the secure multi-party computation protocol. 30. The apparatus for obtaining input to a secure multi-party computation protocol according to claim 29, wherein the verification data is the ledger location obtained by the method according to claim 4, wherein the ledger location is stored in the There is the first ciphertext obtained by the method according to claim 1, Wherein, the verification unit includes: a first obtaining subunit, configured to obtain the first ciphertext through the account book location; and The first determination subunit is configured to determine whether the second ciphertext is the same as the first ciphertext. 31. The device for obtaining the input of a secure multi-party computation protocol according to claim 29, wherein the verification data is the account book position obtained by the method according to claim 5, and the account book position is stored with The hash value of the first ciphertext obtained by the method according to claim 5, Wherein, the verification unit further includes: A second obtaining subunit, configured to obtain the hash value of the first ciphertext through the location of the ledger; and The second determination subunit is configured to determine whether the second ciphertext matches the hash value. 32. A device for obtaining the input of a secure multi-party computation protocol, the participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, the The secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in a second server side, the second server side is a server side of an authority, and the device is in The third server-side implementation includes: a receiving unit, configured to receive, from the first server, the ledger location obtained by the method according to claim 4; and The obtaining unit is configured to obtain the first ciphertext from the ledger position as an input of the secure multi-party computation protocol. 33. A device for obtaining the input of a secure multi-party computation protocol, the participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, the The secure multi-party computation protocol performs computation based on first data of the first object, wherein the first data is stored in the first server, and the apparatus is implemented on the third server, including: a receiving unit, configured to receive, from the first server, the ciphertext and the account book location obtained by the method according to claim 10; a verification unit configured to verify the ciphertext using the ledger location to determine whether the ciphertext corresponds to the first data; and The determining unit is configured to, in the case of determining that the ciphertext corresponds to the first data, determine that the ciphertext is used as the input of the secure multi-party computation protocol. 34. A device for obtaining the input of a secure multi-party computation protocol, the participants of the secure multi-party computation protocol include a first server end and a third server end, the first server end is the server end of the first object, the The secure multi-party computation protocol performs computation based on the first data of the first object, wherein the first data is stored in the first server side, and the apparatus is implemented on the third server side, including: a receiving unit configured to receive, from the first server side, the ledger location obtained by the method according to claim 11; and An obtaining unit, configured to obtain the ciphertext from the ledger location as an input of the secure multi-party computation protocol. 35. A computing device, comprising a memory and a processor, wherein executable code is stored in the memory, and when the processor executes the executable code, the execution of any one of claims 1-17 is implemented. method described.

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